JP2013541140A - Process for producing a solvent mixture having a low water content - Google Patents

Abstract

（Ｂ）式（ＩＩａ）又は（ＩＩｂ）で表わされる少なくとも１種の化合物
【化２】

（Ｃ）任意に、芳香族化合物、スルトン及びエキソメチレンエチレンカーボネート、メラミン、尿素、有機ホスフェート、及びハロゲン化有機カーボネートから選択される少なくとも１種の添加剤、
（Ｄ）任意に、少なくとも１種のリチウム塩、
及び３〜３０質量ｐｐｍの水を含む溶媒混合物の製造方法であって、
（ａ）成分（Ａ）、（Ｂ）及び使用する場合は（Ｃ）を互いに混合する工程、
（ｂ）少なくとも１種のイオン交換体又は分子篩を介して乾燥する工程、
（ｃ）イオン交換体又は分子篩からそれぞれ分離する工程、及び
（ｄ）使用する場合は少なくとも１種のリチウム塩を添加する工程を有し、
前記変数が、以下：
Ｒ^１，Ｒ^２は、それぞれ同一であるか、あるいは異なっており、且つＣ_１−Ｃ_４−アルキルから選択され、
Ｒ^３は、水素及びＣ_１−Ｃ_４−アルキルから選択される
ように定義されていることを特徴とする製造方法。
【選択図】なし(A) at least one compound of the formula (I)

(B) at least one compound of the formula (IIa) or (IIb)

(C) optionally at least one additive selected from aromatics, sultone and exomethylene ethylene carbonate, melamine, urea, organic phosphates, and halogenated organic carbonates;
(D) optionally at least one lithium salt;
And a method for producing a solvent mixture comprising 3 to 30 ppm by mass of water,
(A) mixing components (A), (B) and, if used, (C) with each other;
(B) drying through at least one ion exchanger or molecular sieve;
(C) a step of separating each from the ion exchanger or molecular sieve, and (d) a step of adding at least one lithium salt when used,
The variables are as follows:
R ¹ and R ² are each the same or different and are selected from C ₁ -C ₄ -alkyl;
R ³ is defined to be selected from hydrogen and C ₁ -C ₄ -alkyl.
[Selection figure] None

Description

(A) At least one compound represented by formula (I)

（Ｂ）式（ＩＩａ）又は（ＩＩｂ）で表わされる少なくとも１種の化合物

(B) at least one compound represented by formula (IIa) or (IIb)

（Ｃ）任意に、芳香族化合物、スルトン及びエキソメチレンエチレンカーボネート、有機ホスフェート、並びにハロゲン化有機カーボネートから選択される少なくとも１種の添加剤、
（Ｄ）任意に、少なくとも１種のリチウム塩、
及び３〜３０質量ｐｐｍの水を含む溶媒混合物の製造方法であって、
ｉ．成分（Ａ）、（Ｂ）及び使用する場合は（Ｃ）を、互いに混合する工程、
ｉｉ．少なくとも１種のイオン交換体又は分子篩を介して乾燥する工程、
ｉｉｉ．イオン交換体又は分子篩からそれぞれ分離する工程、及び
ｉＶ．使用する場合は、少なくとも１種のリチウム塩を添加する工程を有し、
前記変数が、以下：
Ｒ^１，Ｒ^２は、それぞれ同一であるか、あるいは異なっており、且つＣ_１−Ｃ_４−アルキルから選択され、
Ｒ^３は、水素及びＣ_１−Ｃ_４−アルキルから選択される
ように定義されることを特徴とする製造方法に関する。

(C) optionally at least one additive selected from aromatic compounds, sultone and exomethylene ethylene carbonate, organic phosphates, and halogenated organic carbonates;
(D) optionally at least one lithium salt;
And a method for producing a solvent mixture comprising 3 to 30 ppm by mass of water,
i. Mixing components (A), (B) and, if used, (C) with each other;
ii. Drying through at least one ion exchanger or molecular sieve;
iii. Separating each from the ion exchanger or molecular sieve, and iV. If used, it has a step of adding at least one lithium salt;
The variables are as follows:
R ¹ and R ² are each the same or different and are selected from C ₁ -C ₄ -alkyl;
R ³ relates to a production process characterized in that it is defined to be selected from hydrogen and C ₁ -C ₄ -alkyl.

In an alternative variant, the present invention performs the drying of the individual components (A), (B) and, if used, (C) or the respective drying of these components before they are mixed. The present invention relates to a method for producing a solvent mixture. Therefore, the present invention also provides
(A) At least one compound represented by formula (I)

（Ｂ）式（ＩＩａ）又は（ＩＩｂ）で表わされる少なくとも１種の化合物

(B) at least one compound represented by formula (IIa) or (IIb)

（Ｃ）任意に、芳香族化合物、スルトン及びエキソメチレンエチレンカーボネート、有機ホスフェート、メラミン、尿素、並びにハロゲン化有機カーボネートから選択される少なくとも１種の添加剤、
（Ｄ）任意に、少なくとも１種のリチウム塩、
及び３〜３０質量ｐｐｍの水を含む溶媒混合物の製造方法であって、
ｉ．成分（Ａ）、（Ｂ）及び使用する場合は（Ｃ）の少なくとも１種を、少なくとも１種のイオン交換体又は分子篩を介してそれぞれ個別に乾燥する工程、
ｉｉ．工程（ｉ）で乾燥した成分からイオン交換体又は分子篩をそれぞれ分離する工程、及び
ｉｉｉ．成分（Ａ）、（Ｂ）、使用する場合は（Ｃ）及び使用する場合は少なくとも１種のリチウム塩を、互いに混合する工程を有し、
前記変数が、以下：
Ｒ^１，Ｒ^２は、それぞれ同一であるか、あるいは異なっており、且つＣ_１−Ｃ_４−アルキルから選択され、
Ｒ^３は、水素及びＣ_１−Ｃ_４−アルキルから選択される
ように定義されることを特徴とする製造方法に関する。

(C) optionally at least one additive selected from aromatic compounds, sultone and exomethylene ethylene carbonate, organic phosphates, melamine, urea, and halogenated organic carbonates,
(D) optionally at least one lithium salt;
And a method for producing a solvent mixture comprising 3 to 30 ppm by mass of water,
i. A step of individually drying at least one of components (A), (B) and, if used, (C) through at least one ion exchanger or molecular sieve,
ii. Separating the ion exchanger or molecular sieve from the components dried in step (i), respectively, and iii. Component (A), (B), if used (C) and if used, at least one lithium salt, mixed with each other,
The variables are as follows:
R ¹ and R ² are each the same or different and are selected from C ₁ -C ₄ -alkyl;
R ³ relates to a process characterized in that it is defined to be selected from hydrogen and C ₁ -C ₄ -alkyl.

The present invention further provides:
(A) at least one compound represented by formula (I),
(B) at least one compound represented by formula (IIa) or (IIb),
(C) optionally at least one additive selected from aromatic compounds, sultone and exomethylene ethylene carbonate, organic phosphates, and halogenated organic carbonates;
(D) and optionally at least one lithium salt,
And a solvent mixture comprising 3 to 30 ppm by weight of water, and also relates to the use of the solvent mixture according to the invention in a lithium ion battery.

  There has long been a search for ways to efficiently store electrical energy. Efficient storage of electrical energy allows electrical energy to be generated when it is advantageous and used when needed.

  Storage batteries such as lead storage batteries and nickel-cadmium storage batteries have been known for decades. Known lead and nickel-cadmium batteries have the disadvantages of relatively low energy density and memory effect. The failure reduces rechargeability and thus reduces the service life of lead acid and nickel-cadmium batteries.

  Lithium ion batteries, often also referred to as lithium ion batteries, are used as an alternative. They provide a higher energy density than batteries based on lead or relatively precious metals.

  Many lithium ion batteries utilize metallic lithium, so they are sensitive to water. Therefore, water is out of the question for the lithium salt used in lithium ion batteries. Instead, organic carbonates, ethers and esters are fully used as polar solvents. Therefore, the literature recommends the use of a water-free solvent for the electrolyte (see WO 2007/049888 etc.).

  However, water-free solvents are inconvenient for production and processing. Many solvents that are inherently convenient for lithium ion batteries contain water on the order of 100 ppm or more. However, such a high proportion of water is not acceptable for many lithium ion batteries. The problem with supplying a sufficiently suitable solvent for lithium ion batteries is that most artificial lithium ion batteries contain a solvent mixture rather than a single solvent, and some of the solvent mixtures These solvents are complicated by the fact that their activity differs significantly from the desiccant.

WO2007 / 049888

  An object of this invention is to provide the solvent mixture suitable as an electrolyte in a lithium ion battery. Another object of the present invention is to provide a method for producing a solvent mixture suitable for a lithium ion battery. An object of the present invention is to provide a lithium ion battery having finally good performance characteristics.

  We have found that this object is achieved by the manufacturing method defined at the beginning.

For the purposes of the present invention, a lithium ion battery is referred to as a lithium ion battery.
The manufacturing method according to the present invention includes:
(A) At least one compound represented by formula (I)

（Ｂ）式（ＩＩａ）又は（ＩＩｂ）で表わされる少なくとも１種の化合物、

(B) at least one compound represented by formula (IIa) or (IIb),

及び３〜３０質量ｐｐｍの、好ましくは５〜２５質量ｐｐｍの水を含む溶媒混合物を提供する。

And a solvent mixture comprising 3 to 30 ppm by weight, preferably 5 to 25 ppm by weight of water.

The variables in the formula are:
R ¹ and R ² are the same or different, and C _{1 of} methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl or the like (preferably methyl or ethyl). -C ₄ - is selected from alkyl,
R ³ is selected from C ₁ -C ₄ -alkyl of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, etc. (preferably methyl), and more specifically from hydrogen. Are defined as follows.

  One embodiment of the present invention provides a compound of formula (I) and compounds of formula (IIa) and (IIb) of 1:10 to 10: 1 and preferably 3: 1 to 1: 1. It is included at a mass ratio in the range.

  Preferred compounds of formula (I) are dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate and mixtures thereof, ie a mixture of at least two of the listed compounds of dimethyl carbonate, diethyl carbonate and methyl ethyl carbonate. .

  In one embodiment of the present invention, the solvent mixture obtained according to the present invention comprises two or more compounds of formula (I) such as diethyl carbonate and methyl ethyl carbonate.

  In one embodiment, the solvent mixture obtained according to the present invention comprises at least one compound of formula (IIa) but does not contain a compound of formula (IIb). In another embodiment of the invention, the solvent mixture obtained according to the invention comprises at least one compound of formula (IIb) but does not contain a compound of formula (IIa). In another embodiment of the invention, the solvent mixture obtained according to the invention comprises at least one compound of formula (IIa) and at least one compound of formula (IIb).

  The proportion of water can be determined by various methods known per se. Karl Fischer titration, such as DIN 51777 or ISO 760: 1978, is particularly suitable.

The solvent mixture obtained according to the invention is
(C) at least one additive selected from aromatic compounds, sultone and exomethylene ethylene carbonate, halogenated organic carbonates, organic phosphates, and / or (D) at least one lithium salt You may go out.

  Thus, “solvent mixtures” for the purposes of the present invention apply not only to salt-free solvent mixtures, but also to lithium salt solutions in solvent mixtures.

  Examples of aromatic compounds suitable as additives are biphenyl, cyclohexylbenzene and 1,4-dimethoxybenzene.

  The sultone may be substituted or unsubstituted. Examples of suitable sultone are butane sultone and propylene sulfone, formula (III),

及び特に１分子あたり少なくとも１個のＣ−Ｃ二重結合を有するスルトンである。置換されたスルトンの例は１−フェニル−１，３−ブタンスルホンである。

And in particular sultone with at least one C—C double bond per molecule. An example of a substituted sultone is 1-phenyl-1,3-butanesulfone.

  Examples of exomethylene ethylene carbonate are especially those of the formula (IV)

［式中、Ｒ^４及びＲ^５はそれぞれ異なっているか、又は同一であることができ、且つそれぞれＣ_１−Ｃ_１０アルキル及び水素から選択される］で表わされる化合物である。好ましい一実施の形態では、Ｒ^４及びＲ^５は共にメチルである。

Wherein R ⁴ and R ⁵ are each different or the same and are each selected from C ₁ -C ₁₀ alkyl and hydrogen. In one preferred embodiment, R ⁴ and R ⁵ are both methyl.

  Halogenated, more specifically fluorinated organic compounds include cyclic or acyclic organic carbonates having at least one halogen atom per molecule, preferably one or more halogen atoms per molecule. The halogen atom is preferably chlorine, more preferably fluorine. For example, the following formula:

で表わされるフルオロエチレンカーボネート及びジフルオロエチレンカーボネートが挙げられる。

And fluoroethylene carbonate and difluoroethylene carbonate represented by the formula:

  The organic phosphate comprises a triester of phosphoric acid with one or more organic alcohols, preferably with one organic alcohol. Useful organic alcohols include substituted or unsubstituted alkanols, substituted or unsubstituted phenols, and the like. Suitable examples of organic phosphates include tris (chloroethyl) phosphate, tris (3-chloropropyl) phosphate, tris (2-isopropyl) phosphate, triphenyl phosphate, tricresyl phosphate, tris (ω, ω′-dichloroisopropyl). Phosphate, tris (2-ethylhexyl) phosphate, resorcinol bis (diphenyl phosphate), mono-, bis- and tris (isopropylphenyl) phosphate ("isopropylated triphenyl phosphate"), and bisphenol A diphenyl phosphate. Organic phosphates can function as flame retardants.

  Melamine and urea are examples of other suitable flame retardants.

  In one embodiment of the present invention, the additive (C) is added in a total amount of 0 to 30% by weight, preferably 1 to 10% by weight, based on the total solvent mixture obtained according to the present invention. including.

In one variation, the method provided by the present invention for producing a solvent mixture comprises at least the following three steps:
(A) A step of mixing the components (A) and (B) and, when used, (C) by stirring each other. Pre-dried or commercially available components (A), (B) and (C) when used can be used.
(B) drying the mixture through at least one ion exchanger or preferably through a molecular sieve.
(C) A step of separating the dried solvent mixture from the ion exchanger or molecular sieve.
(D) A fourth optional step of adding at least one lithium salt or component (C).

In another variation, the method provided by the present invention for producing a solvent mixture comprises at least the following three steps:
i. Drying at least one of components (A), (B) and, if used, (C), individually, via at least one ion exchanger or molecular sieve;
ii. Separating the ion exchanger or molecular sieve from the components dried in step (i), respectively, and iii. Mixing the components (A), (B), (C) if used and at least one lithium salt if used together.

  In this modification, it is not necessary to add all the components (A) and (B) and (C) when used in the drying step. One, one or more or all of these components must be dried such that after mixing, the solvent mixture of these components and at least one lithium salt (D) contains a proportion of water according to the present invention. I must.

  The drying of the individual components according to step (i) is carried out in a manner corresponding to the drying of the solvent mixture according to step (b). Similarly, the separation of the dried individual components from the ion exchanger or molecular sieve according to step (ii) is carried out in a manner corresponding to the separation of the dried solvent mixture from the ion exchanger or molecular sieve according to step (c). Is done. Finally, the mixing of the individual components according to step (iii) is carried out in a manner corresponding to the mixing according to step (a).

  Steps (a), (b) and (c) will be described more specifically.

  Mixing of components (A), (B) and (C), if used, can be carried out at the desired temperature.

Step (a):
One embodiment of the invention includes mixing at a temperature in the range of 10-100 ° C.

  One embodiment of the present invention includes mixing at a temperature at least 1 ° C. above the melting point of the highest melting component (A) or (B).

  The upper temperature limit for the mixing operation is determined by the volatility of the most volatile components in the solvent mixture. It is preferred to mix at a temperature below the boiling point of the most volatile component of the solvent mixture.

  Mixing can be carried out at the desired pressure, and atmospheric pressure is preferred. The duration of mixing can be selected, for example, in the range of 5 minutes up to 24 hours.

Step (b):
Ion exchangers and molecular sieves are known per se.

  In the following, the molecular sieve is preferably selected from natural and synthetic zeolites which may take the form of spheres (beads), powders or rods. It is preferable to use a 4Å molecular sieve, more preferably a 3Å molecular sieve.

  The ion exchanger can be used as a molded product in the form of beads or rods, as a powder, or as a column. It is preferable to use a molded product, particularly a molded product such as beads.

  One embodiment of the invention includes using a cationic ion exchanger.

In one embodiment of the invention, the ion exchanger or molecular sieve is selected from an at least partially lithiated ion exchanger or an at least partially lithiated molecular sieve, respectively. At least partially lithiated ion exchangers include cationic ion exchangers in which H ⁺ and / or Na ⁺ or K ⁺ are very substantially substituted by Li ⁺ . In other embodiments of the invention, ion exchangers or molecular sieves are used (even partially) that are not lithiated.

  One embodiment of the present invention is preferably a molecular sieve or preferably a mixture of the solvent from step (a), such as by stirring a molecular sieve or suspension of ion exchangers in the solvent mixture continuously or at specific intervals. Includes mixing with an ion exchanger and allowing the molecular sieve or ion exchanger to interact with the solvent mixture. Instead of stirring, shaking or pump circulation can also be used.

  Other embodiments allow the solvent mixture to be applied as a stationary phase to a column or filter region containing the ion exchanger / molecular sieve and then allow the solvent mixture to pass through the column / filter (eg, under gravity Or by increasing by pumping) the ion exchanger / molecular sieve with the solvent mixture.

It is preferred to allow the ion exchanger or molecular sieve to act on the solvent mixture in the absence of a chemical desiccant. The chemical desiccant for the purposes of the present invention is a strongly acidic, strongly alkaline or strongly reducing desiccant, more specifically selected from low molecular weight compounds, salts and elements. Known acidic desiccants include, for example, aluminum alkyls such as trimethylaluminum, and also phosphorus pentoxide and concentrated sulfuric acid. Known basic desiccants include potassium carbonate, CaH _{2 and the} like. Known reducing desiccants include elemental sodium, elemental potassium, sodium-potassium alloys, and the like.

  One embodiment of the present invention comprises performing step (c) at a temperature in the range of 4-100 ° C, preferably in the range of 15-40 ° C, more preferably in the range of 20-30 ° C.

  In one embodiment of the invention, the time allowed for the ion exchanger or molecular sieve to interact with the solvent mixture is from a few minutes (eg, at least 5 minutes) to a few days (preferably less than 24 hours, and more preferably 1 to 6 hours).

  In one embodiment of the invention, the ion exchanger or molecular sieve is used after filling the tower. This type of embodiment is preferably operated at a linear flow rate (flow rate / empty tower cross section) of 0.1 to 50 m / h, and preferably 0.5 to 15 m / h.

  During the execution of step (c), a small amount of the solvent mixture can be removed one or more times so that the progress of drying is followed by Karl Fischer titration.

  Agitation or shaking is preferably kept to a minimum. Excessive vigorous stirring / shaking can result in partial collapse of the molecular sieve or ion exchanger. And this can cause problems for removal by filtration.

  The action of the ion exchanger / molecular sieve results in substantial removal of traces of the presence of water and acid from the solvent mixture. However, some water remains in the solvent.

Step (c)
After the action of the molecular sieve or ion exchanger on the solvent mixture, it is necessary to separate the molecular sieve or ion exchanger. Separation in step (c) can be achieved by distillation or decantation of the solvent mixture, or preferably by filtration.

  Step (c) is preferably carried out under an inert gas such as dry nitrogen or dry argon. However, instead of dry inert gas, step (c) can also be carried out under dry air.

  The solvent mixture is applied to the column or filter surface containing the ion exchanger / molecular sieve as a stationary phase, and then the solvent mixture is passed through the column / filter amount to perform steps (b) and (c) simultaneously. The selection of possible variants is likewise within the scope of the invention.

  When using a molecular sieve / ion exchanger in the form of beads or rods, the pore size of the filter material is preferably matched to the average particle size of the molecular sieve / ion exchanger.

  One variation involves adding one or more components (C) in whole or in part after step (c).

Step (d)
If desired, at least one lithium salt (D) can be added in step (d) and preferably dissolved. Suitable lithium salts (D) must be sufficiently dissolved in the solvent mixture obtained according to the invention, for example at least 1 g / l at room temperature. Examples of suitable lithium salts (D) are LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , LiCF ₃ SO ₃ , LiC (C _n F _{2n + 1} SO ₂ ) ₃ , lithium bisoxalate borate, lithium difluorobisoxa _{Ratoborato, LiN (C n F 2n +} 1 SO 2) 2 and lithium imide (where, n is an integer of _{1~20), LiN (SO 2 F} ) 2, LiSiF 6, LiSbF 6, LiAlCl 4, And the general formula (C _n F _{2n + 1} SO ₂ ) _m XLi
[Where m is defined as follows:
m = 1, when X is selected from oxygen and sulfur, m = 2, when X is selected from nitrogen and phosphorus, and m = 3, when X is selected from carbon and silicon] is there.

Preferably formulated salts are selected from LiC (CF ₃ SO ₂ ) ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiPF ₆ , LiBF ₄ and LiClO _4, especially LiPF ₆ and LiN (CF ₃ SO ₂ ) ₂ preferable.

  In addition to adding the lithium salt (D) in step (d), the solvent mixture can be heated and / or subjected to further methods such as shaking, stirring or pumping to facilitate dissolution of the lithium salt. .

  One embodiment can include the addition of 1-30 wt% lithium salt (D), preferably in the range of 10-20 wt%, based on the total solvent mixture obtained by the present invention.

  In a variant of the invention, one or more additives (C) can be added after carrying out steps (a) to (c). However, it is only advisable if the additive (C) does not raise the total water content of the solvent mixture obtained according to the invention to more than 30 ppm by mass.

  In one variant of the invention, at least one further component (B) can be added beyond component (B) initially mixed with component (A).

  The solvent mixture obtained by the method of the present invention is very suitable for and for the production of lithium ion batteries.

The present invention further provides (A) at least one compound represented by formula (I)

（Ｂ）式（ＩＩａ）又は（ＩＩｂ）で表わされる少なくとも１種の化合物、

(B) at least one compound represented by formula (IIa) or (IIb),

（Ｃ）任意に、芳香族化合物、スルトン、エキソメチレンエチレンカーボネート、有機ホスフェート、メラミン、尿素及びハロゲン化有機カーボネートから選択される少なくとも１種の添加剤、特に、１種以上のフッ素化有機カーボネート、
（Ｄ）任意に、少なくとも１種のリチウム塩、
及び３〜３０質量ｐｐｍの水、好ましくは５〜２５質量ｐｐｍの水を含む溶媒混合物であって、
上記変数が、以下：
Ｒ^１，Ｒ^２は、それぞれ同一であるか、あるいは異なっており、且つＣ_１−Ｃ_４−アルキルから選択され、
Ｒ^３が、水素及びＣ_１−Ｃ_４−アルキルから選択される
ように定義されること特徴とする溶媒混合物を提供する。

(C) optionally at least one additive selected from aromatic compounds, sultone, exomethylene ethylene carbonate, organic phosphates, melamine, urea and halogenated organic carbonates, in particular one or more fluorinated organic carbonates,
(D) optionally at least one lithium salt;
And 3 to 30 ppm by weight of water, preferably 5 to 25 ppm by weight of water,
The above variables are as follows:
R ¹ and R ² are each the same or different and are selected from C ₁ -C ₄ -alkyl;
Providing a solvent mixture, characterized in that R ³ is defined as selected from hydrogen and C ₁ -C ₄ -alkyl.

  The solvent mixture according to the present invention is advantageously obtained by the method according to the present invention.

  Components (A), (B) and water and optional components (C) and (D) are as described above.

  In one embodiment of the invention, the solvent mixture according to the invention does not contain measurable proportions of alcohols or protic organic compounds such as primary or secondary amines.

  In one embodiment of the invention, the solvent mixture according to the invention comprises 50 ppm by mass or less, preferably 20 ppm by mass or less, and more preferably 10 ppm by mass of protic organic compound.

In one embodiment of the invention, the solvent mixture according to the invention comprises
A total of 9 to 90% by weight, preferably 20 to 80% by weight of compounds of the formula (I),
A total of 9 to 90% by weight, preferably 20 to 80% by weight of compounds of the formula (IIa) or (IIb),
3-30 ppm by weight, preferably 5-25 ppm water,
0-30% by weight in total, preferably 1-10% by weight of additive (C),
A total of 0 to 30% by mass, preferably 10 to 20% by mass of lithium salt (D) is contained.

  In one embodiment of the invention, the compound of formula (I) is dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, and mixtures thereof, ie, the listed compounds dimethyl carbonate, diethyl carbonate and methyl ethyl carbonate. It is selected from at least two mixtures.

  In one embodiment of the invention, the solvent mixture according to the invention comprises at least one compound of the formula (IIa) and at least one compound of the formula (IIb).

In one embodiment of the present invention, the solvent mixture according to the present invention is LiPF ₆ , LiBF ₄ , LiN (CF ₃ SO ₂ ) ₂ , LiClO ₄ , lithium bisoxalate borate, lithium difluorooxalate borate, LiAsF. ₆ , LiN (FSO ₂ ) ₂ , LiC (CF ₃ SO ₂ ) ₃ , LiN (C ₂ F ₅ SO ₂ ) _2, at least one lithium salt (D) selected from LiPF ₆ , LiBF ₄ , LiN (CF ₃ SO ₂ ) ₂ and lithium bisoxalate borate (LiBOB) are preferred.

  The lithium salt (D) can be added to the solvent mixture at a concentration of 0.1M to 3M, preferably 0.5M to 1.5M.

In one embodiment of the present invention, the solvent mixture according to the present invention contains a total of less than 50 ppm by mass of decomposition products of the compounds represented by formulas (I), (IIa) and / or (IIb). The decomposition products are, for example, aliphatic C ₁ -C ₄ -alkanols, ethylene glycol or the general formula

［式中、Ｒ^３はそれぞれ上記の通りである。］で表わされる化合物である。

[Wherein R ³ is as defined above. ] It is a compound represented by this.

Decomposition products such as aliphatic C ₁ -C ₄ -alkanols, ethylene glycol, or compounds of the above formula can be detected by gas chromatography or the like.

  The solvent mixture according to the invention in a preferred embodiment does not contain measurable proportions of degradation products in the compounds of formula (I), (IIa) and / or (IIb).

  The solvent mixture according to the invention is very useful for and for the production of lithium ion batteries. Accordingly, the present invention further provides a method for using the solvent mixture according to the present invention during or for the production of lithium ion batteries. The present invention further provides a lithium ion battery comprising the solvent mixture according to the present invention. The lithium ion battery according to the present invention exhibits good cycleability and excellent stability. The lithium ion battery utilizes a solvent mixture according to the present invention that includes at least one lithium salt (D).

Lithium ion battery according to the present invention, for example, based on transition metal mixed oxide _(such as based on _{LiMnO 2, LiCoO 2, LiNiO 2} , Li 1 + w (Ni a Co b Mn 1-a-b) 1-w O One or more cathodes (based on ₂ ) may be included. Here, w can be in the range of 0-0.2 (preferably up to a maximum of 0.1), and a and b are selected from a number in the range of 0-1. However, it follows the condition of a + b ≦ 1.

  Cathodes based on transition metal mixed oxides may further include, for example, carbon in a conductive form such as carbon black, soot, graphite, graphene, or as carbon nanotubes.

  The cathode in the battery according to the present invention may further contain a binder such as a polymer binder. Particularly suitable polymer binders are polyvinylidene fluoride (PVdF), polytetrafluoroethylene, copolymers of tetrafluoroethylene and hexafluoropropylene, copolymers of tetrafluoroethylene and vinylidene fluoride, and polyacrylonitrile. It is.

  The lithium ion battery according to the present invention may further comprise an anode made of a material known per se, preferably substantially graphite. The lithium ion battery according to the present invention may further include conventional components such as one or more separators, one or more current collectors, and a housing.

In another embodiment of the present invention, the lithium ion battery according to the present invention is a so-called lithium air battery, that is, an oxide or a peroxide is formed by a reversible reaction of lithium with atmospheric oxygen (that is, Li ₂ O Or a battery based on the principle of forming Li ₂ O ₂ . The lithium ion battery according to the present invention in another embodiment of the present invention is a lithium-sulfur battery, that is, S ²⁻ (S ²⁻ is re-oxidized when the cell is charged) via sulfur polysulfide ions. May be selected from batteries based on the reaction to

  The invention is illustrated by examples.

  All ppm values are based on ppm by mass. The determination is by Karl Fischer titration with coulometric detection as per DIN 51777 or ISO 760: 1978.

I. Production of lithium ion battery according to the present invention 1 Solvent mixture LGM. Manufacture of 1 Zeolite based aluminosilicate on HS1000 filter, in the form of beads having an average particle size of 16 mm, 3 kg of molecular sieve 37 kg marketed as Sylobeed® MS564C, its filter surface being a suction filter It was activated by heating to 150 ° C. over 114 hours at 1 MPa (10 bar) on the upper filter.

  The following were mixed at 25 ° C. under dry argon in a stirred vessel connected to a suction filter in the pump circuit.

78.2 kg of ethylene carbonate (II.a.1), water content: 20 ppm
97.6 kg of ethyl methyl carbonate (I.1), water content: 53 ppm
The organic carbonate mixture thus obtained was pumped through a molecular sieve in a suction filter. After 7.5 hours, a solvent mixture according to the invention having a water content determined as 15 ppm was obtained. As a result, the solvent mixture LGM. In order to obtain 1, 31.0 kg LiPF ₆ and 4.4 kg vinylene carbonate were dissolved.

I. 2 Production of Lithium Ion Battery Electrode According to the Present Invention 2.1 Manufacture of the cathode The following:
89 g Li _1.01 Ni _0.5 Co _0.2 Mn _0.3 O _2.01
5 g PVdF (from Aldrich)
3 g of carbon black (Super-P (registered trademark), derived from Timcal)
3g of carbon black (from KS6, Timcal)
Were mixed in a mortar under argon with the addition of 100 g of NMP until a honey-like suspension was formed. The honey-like suspension was blade coated onto aluminum foil and dried at 120 ° C. for 16 hours. The layer thickness of the dry cathode mass thus obtained was 40 μm. The layer was rolled and compressed to 30 μm in 25% increments. The electrode was then cut to a size of 50 mm x 50 mm, weighed, welded to an Al current collector and dried once again at 120 ° C under vacuum.
The determined active mass for the cathode was 225 mg.
I. 2.2 Manufacture of lithium ion battery according to the present invention The dry electrode from 2.1 was transferred to an argon filled glove box. Within the glove box, the following operation was performed: the anode was placed on a heat-sealable PET / Al / PE composite film (NEFAB) with its coated side up and about 500 μL of LGM. 1 was dripped. A polyolefin separator (Celguard) having a size of 55 mm × 55 mm was placed in the center of the electrode moistened with the electrolyte without any crease, and LGM. 1 was dripped. Next, LGM. 1 was dripped and placed in the center of the separator with its coated side down. Finally, an excess amount of LGM. 1 was wiped off, and the laminate (PET / Al / PE composite film, anode, separator, cathode) was wrapped with a heat-sealable PET / Al / PE composite film and sealed on four sides using a heat sealer.

  The lithium ion battery LIB. 1 was obtained.

II. The lithium ion battery LIB. 1 Electrochemical characterization:
LIB. 1 was removed from the glove box and charged and discharged at 25 ° C. (while measuring battery capacity) using a battery test system (MACCOR) using the following settings:
Charging: 3.2 V to 4.2 V at the stated C rate, then maintained at 4.2 V for 1 hour Discharge: 4.2 V to 3.2 V at the stated C rate Current: 0.1 C (forming) 1 and 2 cycles, and 3 to 300 cycles at 0.5C. The specific capacity C was set at a nominal value of 139 mAh / g.

result:
LIB. One cycle dependent capacity and also charge / discharge efficiency is shown in FIG. It is clear that the capacity of 135 mAh / g (based on the cathode material) measured in the third cycle has hardly decreased during the charge / discharge process. After 300 cycles, the capacity was still 128 mAh / g. This corresponds to a reduction of only 5%. After only a few cycles, charging and discharging were performed with high efficiency (over 99.95%).

Claims (15)

(A) At least one compound represented by formula (I)

(B) at least one compound represented by formula (IIa) or (IIb)

(C) optionally at least one additive selected from aromatic compounds, sultone and exomethylene ethylene carbonate, organic phosphates, melamine, urea, and halogenated organic carbonates;
(D) optionally at least one lithium salt;
And a method for producing a solvent mixture containing 3 to 30 ppm by mass of water,
(A) mixing components (A), (B) and, if used, (C) with each other;
(B) drying through at least one ion exchanger or molecular sieve;
(C) a step of separating each from the ion exchanger or molecular sieve, and (d) when used, a step of adding at least one lithium salt,
The variables are as follows:
R ¹ and R ² are each the same or different and are selected from C ₁ -C ₄ -alkyl;
R ³ is defined to be selected from hydrogen and C ₁ -C ₄ -alkyl. (A) At least one compound represented by formula (I)

(B) at least one compound represented by formula (IIa) or (IIb)

(C) optionally at least one additive selected from aromatic compounds, sultone and exomethylene ethylene carbonate, organic phosphates, melamine, urea, and halogenated organic carbonates;
(D) optionally at least one lithium salt;
And a method for producing a solvent mixture containing 3 to 30 ppm by mass of water,
i. Drying at least one of components (A), (B) and, if used, (C), individually, via at least one ion exchanger or molecular sieve;
ii. Separating the ion exchanger or molecular sieve from the components dried in step (i), respectively, and iii. Component (A), (B), if used (C) and if used, at least one lithium salt, mixed with each other,
The variables are as follows:
R ¹ and R ² are each the same or different and are selected from C ₁ -C ₄ -alkyl;
R ³ is defined to be selected from hydrogen and C ₁ -C ₄ -alkyl.   The manufacturing method of Claim 1 or 2 in which the said solvent mixture contains 5-20 mass ppm water.   The production method according to any one of claims 1 to 3, wherein the ion exchanger or the molecular sieve is separated by filtration in the step (c).   The process according to any one of claims 1 to 4, wherein the ion exchanger or molecular sieve is each selected from at least partially lithiated ion exchangers or at least partially lithiated molecular sieves.   The production method according to any one of claims 1 to 4, wherein the ion exchanger or molecular sieve is selected from a non-lithiated ion exchanger or a non-lithiated molecular sieve, respectively.   The production method according to any one of claims 1 to 6, wherein the compound represented by the formula (I) is selected from dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, and a mixture thereof.   The production method according to any one of claims 1 to 7, wherein at least one compound represented by the formula (IIa) and at least one compound represented by the formula (IIb) are selected. a. At least one compound of formula (I)

b. At least one compound of formula (IIa) or (IIb)

c. Optionally, at least one additive selected from aromatics, sultone and exomethylene ethylene carbonate, organic phosphates, and halogenated organic carbonates;
d. Optionally, at least one lithium salt,
And a solvent mixture comprising 3 to 30 ppm by weight of water,
The variables are as follows:
R ¹ and R ² are each the same or different and are selected from C ₁ -C ₄ -alkyl;
A solvent mixture characterized in that R ³ is defined as selected from hydrogen and C ₁ -C ₄ -alkyl.   The solvent mixture according to claim 9, comprising 5 to 25 ppm by weight of water.   The solvent mixture according to claim 9 or 10, wherein the compound represented by formula (I) is selected from dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, and mixtures thereof.   The solvent mixture according to any one of claims 9 to 11, comprising at least one compound represented by formula (IIa) and at least one compound represented by formula (IIb). Lithium salt (D) _{is, LiPF 6, LiBF 4, LiN} (CF 3 SO 2) 2, and solvent mixtures according to any one of claims 9 to 12 which is selected from lithium bis oxalate borate.   The method of using the solvent mixture of any one of Claims 9-13 for manufacture of a lithium ion battery.   The lithium ion battery containing the solvent mixture of any one of Claims 9-13.